The present invention relates generally to systems and methods for measuring parameters of a fluid stream. More particularly, the invention relates to an inferential densometer and mass flowmeter.
Certain exemplary embodiments of existing densometers utilize radioactive elements to measure the density of fluids. The use of such radioactive densometers may be problematic because of the need for additional procedures and precautions to ensure the densometer is handled safely. The use of existing non-radioactive densometers, such as Coriolis meters, is also problematic. For example, the largest embodiments of such meters typically have a flow area of no larger than about 3 inches in diameter; however, most subterranean treatment operations employ fluid piping having about a 4 inch to about an 8 inch diameter. Thus, conventional non-radioactive densometers, even in their largest embodiments, cannot accommodate the flow of the entire stream for most subterranean treatment operations. Accordingly, the majority of the flow is typically piped around such non-radioactive densometers, through a 1 inch or 2 inch diameter bypass pipe, while only a small portion of the flow is actually measured through the densometer. Accordingly, one cannot be certain that such a non-radioactive densometer is measuring a representative portion of the flow stream.
Pressure limitations also pose a problem for conventional non-radioactive densometers. Such densometers typically are limited to a maximum fluid pressure of between 150 psi to about 300 psi. However, numerous subterranean treatment operations are conducted at operating pressures of up to about 15,000 psi, which often necessitates the use of densometers that have been proven to withstand “proof” pressures of up to about 22,500 psi. Accordingly, conventional non-radioactive densometers are suitable only for low pressure applications.